1. Field of the Invention
This invention relates to the packaging and shipping art, and more particularly relates to containers for packaging and shipping substantially flat frangible items, such as glass doors.
2. Description of the Prior Art
The problems of shipping flat, frangible items, such as glass sheets and products containing glass sheets such as windows, doors and the like, have been with manufacturers and shippers for some time. In general, the problems revolve around attempts to prevent the frangible item from breaking, chipping or cracking. Many arrangements have been devised in the past to solve these problems. Many of these attempts significantly improved the packaging and shipping containers, and when taken individually or in conjunction with selected other attempts, have reduced the risk of breakage, cracking and chipping during storage and shipment.
Early attempts to solve the problem centered around securing the frangible items in as protective a covering as possible. Most often, such a protective envelope included rigid, hard containers usually made of wood or stronger material. The frangible items were arranged tightly within wood boxes or crates having stuffed therein a very large amount of packing material, such as excelsior, plastic form, newsprint, shavings, sawdust and the like.
Improvements were made in the particular wrapping arrangements securing the products within such boxes. One such improvement includes the interlocking of strips of paperboard so as to hold the strips in a folded, accordian-like position. The accordian-like paperboard is then secured around the entire periphery of the frangible product and acts as a packing between the frangible product and the shipping frame. A representative example of such packing can be seen in the patent to Freiberg, U.S. Pat. No. 2,626,050. Such packing arrangements, however, still require an all covering shipping container or carton which, for the most part, hides the nature of the frangible products being shipped.
Hereinafter in this description, the term "box" will be used interchangeably with, and is intended to have a meaning synonymous with the terms "carton" and "case". Also, the terms "cardboard" and "fibreboard" will be used interchangeably with the term "paperboard" to denote paper formed in a board-like fashion or pasted together in pasteboard.
With the nature of the products being shipped and packed hidden from view of the shippers and packers, breakage, chipping and cracking of the frangible products are not discovered until the package arrives at a customer's facility when the shipping and packing containers are unwrapped. Where, along the line from the manufacturing plant to the customer's receiving dock, the items was actually cracked, chipped or broken, can not be immediately determined. Aside from the issue of liability on the part of one or more of the shippers involved, there is an undesirable delay in supplying substitute frangible items.
If a frangible product were damaged enroute, and if it could be determined immediately after such damage that such had occured, the fact of such damage could be immediately conveyed to the manufacturer or the customer, and substitute products could be shipped at once. Significant savings of time for often important and critical items in the manufacture of larger items could be realized. A builder of a building could more speedily have necessary windows; or, the builders of end items, such as refrigerated display cabinets, could have replacement doors supplied more speedily.
While such packaging arrangements improved the security of the frangible items, breakage continued to occur. It is reasoned that some of this breakage, cracking and shipping continued to occur because the armor-like cases, aside from hiding the nature of the product so-wrapped from the view of shipping and storing persons, created an image of invulnerability. Thus, these heavy wooden shipping containers were dropped from loading platforms, stacked unreasonably high one upon another, rammed by store room dollies and forklift trucks and otherwise handled in a manner in excess of the safety actually provided by the heavy wood crate. Indeed, the very weight of such shipping containers may have added to the difficulty in handling and thereby abetted shipping persons to mishandle the containers. Still, for very rigid structures such as glass doors, in small quantities, wood continues to be the material of choice. See J. F. Hanlon, Handbook of Package Engineering (1971), McGraw-Hill, at page 15-2.
Merely increasing the amount of packaging material and the thickness and weight of the outside, armor-like containers frequent results in only marginal risk improvement. Certainly adding such packing and crating material adds significantly to the weight, and substantially to the shipping costs.
It has been the state of the art and the custom of the industry, apparently, to accept the weight caused by wood or similar heavy boxes or crates for shipping frangible items, since it has been considered that maximum safety can be achieved with rigidity. If rigidity, stacking strength and protection from the hazards of shipping are essential, textbooks written by experts in recent years state that it is difficult to find a better material than wood. See Handbook of Package Engineering cited above, at page 15-3. The patented art showing rigid shipping containers and rigidly packed frangible items is quite developed.
Such rigid containers, however, have a serious drawback in that when they are manufactured, their dimensions are set and usually cannot be varied. Even in the fibreboard containers which are creased for later folding into a container, the dimensions of the ultimate container are preordained by the cut and the fold creasing scheme. Thus, if a group of differently dimensioned items are to be shipped, a separate set of wood boxes or paper slotted containers, commonly called an RSC, must be obtained for each different item size. Moreover, rigidity often means wood and abundant packing material. Shipping costs based on weight, and packing material costs combine to make it desirable to reduce the actual amount of material used in containing and in spacing such flat frangible products.
A significant improvement in the reduction of weight of frangible item shipping packages is described in U.S. Pat. No. 3,990,576 issued to the present inventor and assigned to the assignee of the present invention. Using the invention of that patent, a stack of frangible items is wrapped with a Sus-wrap material, a folded and slotted material for receiving the edges of the frangible items. The wrapped items are secured to a pallet and cinched with strapping means. That invention, while solving many problems, leaves some problems unresolved. The package results in some resiliency, particularly in the upper portions of the package. The resulting top part of the package, however, is such that stacking several packages on top of each other is not easily facilitiated.
As may be appreciated from a closer examination of the invention of that earlier patent to the present inventor, interiorly packaged doors in a package container may not necessarily rest upon the film, rigid pallet. It is possible that such interiorly packaged doors will rest only on the cardboard Sus-wrap suspended between the uppermost rails of the pallet. Such a suspension and attendant lack of wood support increases the risk of cardboard splitting with attendant weakening of the overall package container.
The above-identified earlier patent to the present inventor, further, contains a standard, rigid wood pallet having some five pieces of lumber. While the package container of that patent substantially reduces weight, it may be appreciated that it is always desirable to achieve further reduction in shipping weight as much as possible without sacrificing protection. It is also desirable to simplify and reduce the cost of the packaging materials as well as to increase the flexibility of the arrangement to package frangible objects having varying dimensions.